The standard pneumatically-driven tool assembly contains a driving head for accommodating a standard socket, which driving head and socket do not define a through hole, and hence such assembly is restricted for use in those situations where the nut or bolt head are readily accessible and do not have an outwardly projecting threaded rod or equivalent.
In addition, many of the standard pneumatic tools do not incorporate a rotation reversing mechanism since the tools, particularly when used in assembly operations, are normally used for driving bolts or nuts in only a single rotational direction. Further, the known pneumatic tools which do provide for rotational reversing generally accomplish such reversing by use of a complex shifting mechanism, such as by shifting interior gears and pawls against the driving yoke, and such reversing mechanisms are typically positioned laterally spaced from the rotational axis of the driven socket.
Accordingly, it is an object of this invention to provide an improved powered driver for a tool, specifically a pneumatic ratchet driver for a socket, which driver not only cooperates with the socket to define a through hole to accommodate extension therethrough of an elongate rodlike member, but which also incorporates a rotational drive reversing mechanism preferably disposed in coaxial relationship to the through opening for permitting simple but manual selection in the direction of rotational drive.
In a preferred embodiment of the invention, the powered tool driver of the invention includes an elongate hollow housing which defines at one end an elongate handle part in which is provided a power-driven rotary motor, the latter effecting rotation of an intermediate drive mechanism which couples to a driving yoke provided adjacent the other end of the housing for effecting angular oscillation thereof. This other end of the housing defines a driving head and includes two cantilevered housing parts which project in generally parallel relationship and define a slot therebetween in which the driving yoke is positioned. The yoke and projecting housing parts define an opening extending therethrough in generally transverse relationship to the elongate direction of the housing, which opening accommodates a reversible socket-driving assembly. This latter assembly includes a tool or socket-driving member rotatably supported on one housing part for removably engaging a socket having a through opening therein. This socket-driving member is coaxially aligned with a drive reversing member which is rotatably supported in the other housing part. The socket-driving and drive reversing members are normally spring-urged toward one another but maintained rotatably isolated from one another through an intermediate bearing. The drive reversing member also has an opening extending coaxially therethrough for alignment and communication with the opening in the socket. The socket-driving member includes a gear portion rotatably positioned within an opening formed in the driving yoke, and the latter mounts thereon first and second spring-urged pawls adapted for engagement with the gear portion to effect driving thereof in opposite rotational directions. The drive reversing member includes a cam part which cooperates with the pawls to control the positions thereof relative to the gear portion. The cam part can be manually rotated into first and second positions which respectively permit solely the first and second pawls to drivingly engage the gear portion to permit rotational driving in opposite directions. The cam part can also be disposed in a third intermediate position, namely a neutral position, whereby both pawls are maintained out of driving engagement with the gear portion. Other objects and purposes of the invention will be apparent to persons familiar with structures of this general type upon reading the following specification and inspecting the accompanying drawings.